• Worldwide distribution. On potato, brassicas, capsicum, carrot, aroids, ornamentals and more. Important bacterial diseases.
• Three kinds: (i) soft rots in seed, brown with black margin, (ii) stem rots (uncommon); (iii) wet rots in storage. Spread in ground water, and trade in tubers.
• Cultural control: certified seed; treat cutting tools (bleach); field drainage; avoid excessive N; avoid irrigation until emergence; avoid harvest when wet, and avoid wounds; harvest 7-10 days after vine are dead; avoid washing tubers before storage; store at 12-15°C for 1-2 weeks, and then at 10°C.
•  Chemical control: none recommended.

Bacterial soft rot

Pectobacterium carotovorum subsp. carotovorum (previously, Erwinia carotovora subsp. carotovora). There are other, related, bacteria species causing stem and tuber rots in potato, most importantly 'black leg' caused by Pectobacterium atrisepticum, and Erwinia chrysanthemi (renamed Dickeya chrysanthemi) causing tuber rots, particularly in tropical countries (see Fact Sheet no. 179).